Apparatus for preventing lost circulation in well drilling operations



, June 18, 1957 Filed July 19, 1954 APPARATUS FOR PR rlllllllp".

G W. BINKLEY EVENTING LOST CIRCULATION IN WELL DRILLING OPERATIONS 2 Sheets-Sheet 1 George W B/n/r/e y,

June 18, 1957 G. w BINKLEY 2,796,134

APPARATUS FOR PREVENTING LOST CIRCULATION IN WELL DRILLING OPERATIONS Filed July 19, 1954 2 Sheets-Sheet 2 F/'g 4 M 3 INVENTOR.

' George W Bink/ey,

United States Patent APPARATUS FOR PREVENTING LOST CIRCULA- TION IN WELL DRILLING OPERATIONS George W. Binkley, Houston, Tex., assignor, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N. J., a corporation of Delaware Application July 19, 1954, Serial No. 444,102

1 Claim. (Cl. 166-207) The'present invention is directed to method and apparatus for preventing lost circulation in boreholes drilled in the earths surface. More particularly, the invention is directed to a method for sealing an area in a borehole in which drilling fluid is being lost. In its more specific aspects, the invention is directed to a method of drilling a borehole penetrating a zone where drilling fluid is lost.

The present invention may be briefly described as a method for preventing lost circulation in a borehole drilled in the earths surface in which drilling fluid is circulated in the borehole and normally returned up the borehole and drilling fluid is being lost during this circulation. The specific feature of the present invention comprises underreaming the borehole in the area where drilling fluid is being lost and then arranging a body of fluid cementitious material in the borehole to fill the underreamed area in confined relationship to the walls of the borehole. The cement is allowed to set in the underreamed area to seal off the zone or area Where fluid has been lost and thereafter drilling operations are conducted through the set cement and through the area where drilling fluid had been lost.

The present invention includes apparatus for forming a sheath in the Well bore which comprises an expansible elongated tubular member provided with means for releasably holding the tubular member in compressed condition. The expansible tubular member is provided with apparatus for lowering the tubular member in the well bore to the underreamed area in compressed condition and thereafter the compressed tubular member is released to form a sheath against the wall of the well bore in the underreamed area.

The cementitious material employed in the practice of the present invention may suitably be a hydraulic cement, such as Portland cement, either of the normal type or slow setting cement. The hydraulic cement may also be an anhydrous gypsum cement. The cementitious material may also be a thermosetting plastic, such as resinous material of the phenol-formaldehyde type. Other thermosetting plastic materials such as ureaformaldehydes and melamine-formaldehydes may be used as the cementitious material in lieu of hydraulic cement. Ordinarily, however, we will prefer to use a hydraulic cement rather than a thermosetting plastic but some conditions will make the use of the latter preferable.

The invention will be further illustrated by reference to the drawing in which:

Fig. 1 illustrates a preferred form of apparatus for carrying out the present invention;

Fig. 2 is a modification of the apparatus of Fig. 1;

Fig. 3 illustrates wire line apparatus for conducting the method of the present invention;

Fig. 4 shows the apparatus of Fig. 3 expanded into position in a borehole; and

Fig. 5 is taken along line 5-5 of Fig. 3.

Referring now to the drawing, numeral 11 designates a tubular mandrel which is adapted to be connected to a pipe string or drill string 12 by a threaded coupling means 13. The tubular mandrel 11 is attached by lefthand threads 14 to a tubular mandrel 15 which is arranged on the mandrel 11. The mandrel 11 is provided with a plurality of ports 16 which communicate with ports 17 of the mandrel 15. The mandrel 15 is provided with a sleeve 18 threadably connected to the mandrel 15 by mating threads 19 to which is attached a deformable elastic member 20 which encloses the ports 16 and 17. The lower end of the elastic member 20 is held against the mandrel 15 by a sleeve 21 which is threada-bly connected by mating threads 22 with the mandrel 15.

Arranged on the lower end of the mandrel 11 is a valve seating member 23 which is connected to the mandrel 11 by mating threads 24.

The end of mandrel 11 is provided with a sealing member 25 arranged in a recess 26 to provide a seal between the mandrel 11 and'the mandrel 15. The mandrel 11 is also provided with sealing members 27 and 28 arranged in recesses 29 and 30, respectively, to form a seal around the ports 16 and 17.

Carried on the exterior of the mandrel 15 and normally closing the port '17 is a plurality of flapper valves 31 which will allow flow through ports 16 and 17 to expand the member 26 and which will resist flow from the exterior of the mandrel 15 through the ports 17 and 16.

The mandrel 11 has an open continuous passageway 32 through which fluids may be flowed and this passageway is designed to be closed by dropping a spherical member 33 through the passageway 32 to seat on the member 23 or by pumping the spherical member 33 down the passageway 32.

The device of the present invention, as illustrated in Fig. l, is designed to be attached to a pipe string and lowered in a well bore 40 which has been underreamed to provide an underreamed zone 41 in a zone 42 where lost returns have occurred in the drilling operations of the well bore 40.

Referring now to Fig. 2 in which identical numerals will be employed to designate identical parts, a pipe string, such as 12, is connected by means of a member 50 by mating threads 51 to an upper section 52 of this embodiment of the present invention. The upper section 52 is connected to a lower section 53 of the embodiment of the present invention by left-hand threads 54. The lower section 53 is provided with a recess 54A in which is arranged an expansion member 55. Attached to the lower section 53 by mating threads 56 is an element 57 which has attached to it at its upper end by a sleeve 58 a deformable elastic member 59. The deformable elastic member is connected to the lower end of the member 57 by a sleeve 60 which is connected thereto by mating threads 61. The member 57 is provided with a plurality of ports 62 which communicate the interior of the member 57 with the space 63 enclosed by the member 59. Threadably connected to the member 57 at an intermediate point by mating threads 64 is a valve seating member 65 which is designed to receive a spherical valve member 66 and close a passageway 67 in the seating member 65.

Arranged within the passageway 68 of the members 52, 53 and 57 is a dart-shaped valve means 69 which is provided with guide means or blades 70 on its upper and lower end-s. This guide member serves to center the device and prevent injury to the sealing means as the member 69 traverses the drill or pipe string.

The dart-shaped member 69 is provided with an extension sleeve 71 which is provided with a plurality of ports 72. The sleeve 71 and the dart-shaped member 69 are sealed against the section 53 by sealing members 73, 74, 75 and 76 arranged, respectively, in recesses 77, 78, 79 and 80.

Likewise, the section 52 is sealed against the section 53 by a sealing means 81 arranged in recess 82.

Referring now to Figs. 3 and 4, a well bore, such as 40, has been underreamed to provide an underreamed area 41 where the zone 42 of lost returns have been occurring. Lowered into the underreamed area 41 on a wire line 90 is a tubular member 91 which has attached to it on its upper end .a fishing head 92 carrying a fishing neck 93. The fishing neck 93 is attached to the wire line 90 by a grab or fishing tool 94 which engages with the neck 93. The tubular member 91 is in compressed condition such that the edge 95 overlaps the edge 96.

The tubular member 91 is held in compressed condition by a plurality of compression bands 97 which are designed to be released by explosive shear pins 98. Explosive shear pins 98 are designed to rupture the bands 97 and release the tubular member 91 allowing it to expand into the underreamed zone 41 as shown in Fig. 4 and form a sheath in the zone 41 against the wall of the underreamed section. An explosive in each of the shear pins 98 is detonated by means of electrical contact conductors 99 extending from the shear pins to the surface of the earth carried in or by wireline 90.

In Fig. 4 a body of fluid cement 100 has been spotted in the tubular member 91 and allowed to seal otf the underreamed area 41 against the section or zone 42 where lost returns have been encountered.

The invention is practiced as follows with respect to Fig. 1.

The apparatus is connected into a pipe string-as has been described. Cement is then pumped down the passageway 32 and a spherical valve member, such as 33, introduced with the cement and pumped down until it seats on the seating member 23 to close off the passageway 32. As the passageway 32 is closed, the cement is pumped out into the space enclosed by the deformable member 20 to expand same into sealing engagement with the walls of the underreamed section 41, as shown. This cement pumping is continued until the member 29 is held tightly against the underreamed section 41 and then pumping is stopped and the cement allowed to set up. Flow back through the ports 17 and 16 is resisted by the flapper valves 31 allowing the cement to be retained in the space 45. After the cement has set, the mandrel 11 is backed off to the left at left-hand threads 14 allowing the mandrel 11 to be pulled from the well. Thereafter the drilling operations are resumed to drill through the set cement in the passageway 32 and allowing operations to be conducted without encountering lost returns in zone 42.

The apparatus left in the hole will suitably be cons'tructed of drillable metal, and the like.

In the embodiment of Fig. 2 similar operations are practiced in that cement is pumped down the passageway 68 and a spherical valve member 66 dropped down passageway 68 to seat on the seating member 65 and close the passageway 67. Cement then flows out the port 62 to fill the space 63 and expand the member 57 into engagement with the walls of the well bore and the underreamed section 41. During the time the cement is being pumped down the dart-shaped member 69 is dropped into the well and pumped down until it engage-s with the walls of section 53 with the ports 72 open to allow the cement to proceed downwardly and out through port 62. After the member 59 has been expanded to contain sufiicient cement, pumping is discontinued and the pressure of the cement below the dart-shaped member is sufficient to force it upwardly to close the port 72 as shown.

The expansion ring prevents the dart-shaped memher, which serves as. a valve, from being blown out of the device. The guides or blades '70 center the device and protect the several sealing members or O-rings during the time the dart-shaped member 69 is being pumped down with the cement.

Referring now to Figs. 3 and 4, a tubular member,

4, such as 91, is constructed, for example, of light weight pipe by splitting same from end to end to form a slot. The light weight pipe is then compressed until it overlaps at the edges of the slot to have an outside diameter less than the diameter of the borehole. The tubular member is then secured in compressed position by compression bands and the like which may be released by explosive shear pins which are timed to rupture the compression hands after a suitable interval of time during which the tubular member 91 may be lowered into the underreamed area 41. On explosion of the explosive shear pin, the compressed tubular member springs out to its original diameter to fill the underreamed zone 41 and form a protective sheath for the. body of cement which is then spotted by circulation or by a dump bailer and the like to fill the section which is to be sealed off. The pipe is then cemented in place and allowed to set up. Thereafter the set cement 100 is then drilled out past the area of lost returns 42.

It is contemplated that rather than a compressed section of pipe a tubular member constructed of a deformable resilient material, such as spring steel, plastic, or rubber may be employed. Where these materials are employed, the tubular member is formed by rolling a sheet of the resilient material into cylindrical form. The linear length of the rolled material is greater than the circumference of the reamed-out section of hole so that an overlapping section will form a seal to prevent the passage of fluid. Where the deformable member is made from plastic or rubber it may have spring bands encased or molded into it to aid the tubular member to expand into the underre-amed section.

It will be seen that the method and apparatus of the present invention is of considerable importance in eliminating and preventing lost circulation in rotary drilling operations in which drilling fluid is normally circulated in the well bore and upwardly therein during the drilling operations. In accordance with the present invention, a zone is underreamed where lost circulation is occurring and a protective sheath is formed or arranged in the zone; a body of cement is then expanded into the underrea-med zone in confined relationship to the wall of the underreanred zone. This allows the cement to set up and form a sealed off section which may be easily drilled out and through for institution of normal drilling operations.

The nature and objects of the present invention having been completely described and illustrated, what I wish to claim as new and useful and to secure by Letters Patent is:

Apparatus for forming a sheath in an underreamed section in a well bore which comprises an inherently expansible, elongated, open-ended tubular member having a single slot extending the length of the tubular member, said tubular member being initially arranged with one edge of the slot slidably rolled in compressed condition under the other edge of the slot, a plurality of vertically spaced, rigid means for releasably holding said tubular member in compressed condition, means on each of said releasable holding means adapted to release said holding means at a predetermined time, a wire line for lowering said tubular member in said borehole and detachable means attached tosaid wire line for supporting said tubular member when in said compressed condition.

References Cited in the file of this patent UNITED STATES PATENTS 341,327 Fay May 4, 1886 1,514,062 McLain Nov. 4, 1924 1,834,434 Starr Dec. 1, 1931 2,047,774 Greene July 14, 1936 2,092,041 Anmentrout et al Sept. 7, 1937 2,504,462 Sprague et al. Apr. 18, 1950 2,583,316 Bannister Jan. 22, 1952 2,708,973 Twinning May 24, 1955 

